In most cases a vulcanized rubber to metal bond is significantly stronger than a glued on or cold bond although there are advantages to both. Even though the vulcanized bond is stronger it is a more labor intensive process needing more machinery to accomplish which ultimately leads to a more expensive product. So depending on the need for bond strength in any specific application or project will determine which process/product will best suit your needs.

In both cases the substrates (what you are bonding rubber to) need to be properly prepared. Take sheet steel for instance; in both cases the steel needs to be de-greased and then prepped in some manner. Some common options for this are sand blasting, grit blasting, grinding or chemical etching.

Once the substrate is prepared cold bond glue can applied to both the substrate and the cured rubber sheet. The two materials are then adhered together and the product is complete. The vulcanization process is much more complex. Bonding primers are applied to the substrate after it is prepared, often in two or more layers. Then a tack cement is generally used to adhere the raw rubber to the substrate to hold it in place during the rest of the process. The raw rubber and substrate are then placed into some type of vessel to apply heat and pressure for curing and bonding. Common vessels are autoclaves, vulcanizers, IR oven or presses equipped with heat platens.

There is generally more trimming involved with vulcanized products before they are ready to be shipped due to the rubber over flow but it is not always the case. If there is a need to replace the rubber applied to the substrate glued on products can often be separated by using certain chemicals to the bond surface. Vulcanized on rubber can only be removed by cutting/grinding the rubber off, chiseling the rubber off, by applying excessive amounts of heat to the substrate or simply burning the rubber off in an appropriate type of oven or kiln.

Once again the strength of the bond is significantly higher when using a vulcanization process resulting in a much higher quality product. But the bottom line is not every application needs the highest quality material to perform up to any given standard or expectation.